This work is designed to investigate how genes determine lifespan in a metazoan organism, the small nematode C. elegans. My approach is to try to isolate mutant organisms with lifespans that are longer or shorter than normal, then to characterize the mutants genetically, physiologically and biochemically to try to find out why the lifespan is altered. I am now investigating possible ways to select for mutant organisms with altered lifespans. I am also characterizing development and aging in normal organisms under various conditions as background data to help in isolating and understanding mutants.